1. Field of the Invention
The present invention relates to a control apparatus and a control method for a drive source, and particularly to a technique for setting a demand value of an output value of a drive source and controlling the output value of the drive source in accordance with the set demand value.
2. Description of the Background Art
Conventionally, an engine in which the value of output torque or the like is determined by an opening position of a throttle valve (hereinafter, also referred to as a throttle opening position) or the like has been known. In general, the throttle opening position is actuated so as to uniquely correspond to a position of an accelerator pedal (hereinafter, also referred to as an accelerator pedal position). However, if the throttle opening position and the accelerator pedal position always uniquely correspond to each other, it is difficult to control drive force of a vehicle or the like irrespective of the intention of a driver, for example in the case where an action of the vehicle is disordered. Therefore, there is a vehicle provided with an electronic throttle valve actuated by an actuator in an engine so as to be capable of controlling the output torque and the like without depending on the accelerator pedal position. In the vehicle provided with the electronic throttle value, it is possible to set demand engine torque based on the action of the vehicle and the like in addition to the accelerator pedal position and control the engine so that actual engine torque is equal to the set demand engine torque.
For example, the demand engine torque determined in accordance with the accelerator pedal position is determined as static demand engine torque. The demand engine torque automatically determined based on the action of the vehicle and the like is determined as dynamic demand engine torque.
Here, the static demand engine torque indicates, for example, engine torque that is to be obtained when the engine is in a steady state and that is to be achieved in the future. The dynamic demand engine torque indicates engine torque that is to be obtained when the engine is in a transition state and that is to be achieved immediately.
Final demand engine torque is determined in accordance with a result of addition/subtraction or comparison between the static demand engine torque and the dynamic demand engine torque.
Japanese Patent Laying-Open No. 2003-129876 discloses selecting a larger one of a primary value of static torque and dynamic torque.
It may be desirable for engine control to achieve demand engine torque obtained, for example, by performing addition/subtraction between static demand engine torque determined in accordance with an accelerator pedal position and dynamic demand engine torque determined as the minimum torque for maintaining an idling state of the engine.
However, since the static demand engine torque and the dynamic demand engine torque have different temporal properties, that is, they are achieved at different time points, the demand engine torque cannot be obtained by simply performing addition/subtraction between the static demand engine torque and the dynamic demand engine torque. Specifically, optimal demand engine torque to be achieved at present cannot be obtained by performing addition/subtraction between demand engine torque to be achieved in the future and demand engine torque to be achieved immediately. Therefore, it is not possible to obtain demand engine torque that can be used for engine control.
Although Japanese Patent Laying-Open No. 2003-129876 describes a case where final demand engine torque is set by comparing static demand engine torque and dynamic demand engine torque, it has no description about a case where final demand engine torque is set by performing addition/subtraction between static demand engine torque and dynamic demand engine torque. Therefore, it has been impossible to set final demand engine torque by performing addition/subtraction between static demand engine torque and dynamic demand engine torque.